Process of manufacturing phosphoric-acid compounds.



I UNITED ISTAWENT OFFICE.

rnmxemsn, OE zorro'r, AND .WILHELM 'womnns, or ILDEHAUSEN, GERMANY;

PROCESS on MANT'IFAOTURING,PHOSPKORIG-ACID COMPOUNDS.

No Drawing.

To all whom 'it may-concern:

Be it known "that we,F EL1x GIESE and VVILHELMWouriaas, citizens of the German Empire, residing at Zoppot, Germany, and Ildehausen a. Harz, Germany, respectively, have-invented certain new and useful Im- 'provements in Processes of Manufacturing nuring purposes. 15

In the process of the invention natural phosphates are'melted' together with artl- I ficial silicates and the melted mass is finely distributed by a blast of commingled steam and air. The phosphoric compounds which are formed by the melting together of the phosphates and of the silicates are transformedby such treatment with a current of steam and air mixture into compounds which are nearly completelysoluble in citric acid. This efiect is obtained-by comparatively small additions of artificial silicates to the natural phosphates so that even poor phosphates can be made available for manuring purposes.

In carrying out the invention it is advisable to, combine the process of manufacturing the artificial silicates with the process of melting the same together with'the natural phosphates. Therefore the invention is car riedfout in a preferred embodiment by melting together the natural phosphate with the raw materials for the artificial silicate which it is intended to bring to react-ion with the phosphate. For instance one may add to 100 parts of a natural Belgian phosphate 45 parts of acid sodium sulfate, 28 partsof limestone and 27 parts of sand. This mixture is melted at a temperature of about 1300 and subdivided by a stream of a mixture of steam and air. The stream of steam and air may be produced by an ejector with steam pressure of 3 to .4 atmospheres. The steam and air current is adapted to throw the molten mass to a distance of about 15 Specification of Letters Patent.

Application filed November 17, 1911. Serial No. 660,892.

Patented May 1912.

m. and to produce such a fine division of it that a poppy-seed like granular material is obtained. In calculating the quantity of raw materials for the silicate'to be formed the contents of the phosphate in substances adapted for forming the silicate are to be taken into consideration, so that-it is not always necessary, to add to the phosphate the whole quantity of raw materials for the formation of the silicate, because a part of same may be contained in the phosphate.

In afurther embodiment of the invent-ion the natural phosphate was melted together with a ready made artificial silicate. In this particular case, for each 100 parts of phosphate 45 parts of silicate were taken, the silicate consisting of one equivalent of alkali silicate and two equivalents calcium silicate. In the case where the natural phosphate contained 26.7% phosphoric acid (P 0 the product obtained by the process of the invention contained 18.2% phos-.

phoric acid and of this 18% was soluble phosphoricacid.

The subdivision of themass in the manner described, by a blast of commingled steam and air is important as'insuring such rate of cooling as has proton most efiective in securing a high degree'of citric solubility in the product. Proper subdivision of the molten mass requiresa high blast-pressure,

and if steam alone-were used under sufficient pressure, its consequent high temperature would render proper cooling impossible asimilarly air alone, by reason of its low specific heat is ineffective as a cooling agent at any pressure which is suitable for subdividing the mass. On the other hand, a mixture of airwith steam gives a satisfactory subdivision of the mass, and at the same time a proper cooling effect.

\Vhat we claim is 1. The herein-described process of preparing readily soluble phosphates, Which consists in melting natural phosphates in presence of the chemical elements of a silicate, and mechanically subdividing and cooling the molten mass by a blast of commingled steam and air.

' 2. The herein-described process of pre- In testimony whereof, we affix our sigsparing readily soluble phosphates, which natures in presence of two Witnesses.

consists in melting natural phosphates in FELIX GIESE.

presence of substances adapted to react 5 with formation of silicates, and Inechani- WILHELM WOLTERg' cally subdividing and cooling the molten Witnesses: mass by a blast of commingled steam and FRIEDA BARTELS, air. v EMMA ZIEHE. 

